DETROIT (AP) – Software designed to fix confusing gear shifters on 1.1 million Fiat Chrysler vehicles didn’t work on 29,000 of them. Now the owners are being asked to return to dealers for another try.

The new software was supposed to make the cars and SUVs shift into park when the driver’s door is opened. But Fiat Chrysler says the change didn’t properly fix 13,000 vehicles in the U.S. and 16,000 elsewhere.

FCA says it’s notifying owners. It says the repairs worked on the rest of the 406,000 that have been fixed worldwide.

The 2014 and 2015 Jeep Grand Cherokee and the 2012 through 2014 Dodge Charger and Chrysler 300 were recalled in April due to complaints from drivers who had trouble telling if the transmission was in “park” after stopping.